The immunohistochemistry core laboratory processed over 4150 cases in 2007, producing about 32,500 immunostained slides for clinical service. The laboratory produces an additional 3000 slides in support of a variety of research projects, requested by both LP clinical researchers and NCI/NIH researchers from outside of LP. The laboratory tests include a panel of over 170+ paraffin reactive antibodies, and 40 additional antibodies for frozen section studies. These include cell of origin diagnostic markers, cell signaling pathway activation markers, proliferation-related markers, and other prognostic markers. At any given time, the laboratory is developing or testing 5 or more novel antibodies for potential clinical or research use. Examples of new antibody tests developed by the service include type specific keratin antibodies, newly developed paraffin reactive CD markers including CD4, CD5, CD8, CD25, CD38, CD138, CD163, CXCL13, tissue specific transcription factors and cell cycle regulators. Examples of the latter include MYF-4, CYCLIN D1, p27, HIF-1a, MITF, TFE3, FOXP3, OCT-2, BOB-1, PU-1, PTEN, p-AKT, p-S6K, p-MTOR and several growth factor receptors such as c-KIT, EGRF, and ERB-2. The immunohistochemistry core laboratory supports translational research of both NCI and NIH researchers, and in 2007/8 provided research support to over 20 different NCI and NIH laboratories. Collaborations resulting in publications in 2008 are attached, and include studies with: Dr. Esta Sterneck -- Role of C/EBP delta gene in ovarian function Dr. Elaine Jaffe -- Transdifferentiation studies in lymphomas Dr. David Vistica -- Immunohistochemical discrimination of ASPL-TFE3 fusion proteins in Alveolar Soft Part Sarcoma Dr. Alex Vortmeyer -- Cancer development in VHL Diseases Dr. Herbert Morse -- Role of IRF-8 in macrophages and B-cells Dr. Wyndham Wilson -- Role of biomarkers in response to novel chemotherapy regimens in lymphomas Among the many other NCI and NIH tenured investigators and clinicians that have utilized the laboratory's resources in the past year are: Dr. Mark Hallett (NINDS) Dr. Theo Heller (NIDDK) Dr. Steven Holland (NIAID) Dr. Steven Jacobson (NINDS) Dr. John Janik (NCI) Dr. David Kleiner (NCI) Dr. Kenneth Kraemer (NCI) Dr. Giovanni Melillo (NCI-Frederick) Dr, Stefania Pittaluga (LP-NCI) Dr. Robert Purcell (NIAID) Dr. Steven Rosenberg (CCR-NCI) Dr. Martha Quezado (NCI) Dr. Maria Tsokos (LP-NCI) Dr. Alan Wayne (CCR-NCI) Dr. Adrian Weistner (NHLBI)